The primary cause of vehicular accidents in the United States is driver error. To lower the rate of driver error it is important to eliminate as much as possible any interference with the driver's vision. Accordingly most if not all vehicles have a windshield wiper system equipped with a fluid reservoir located under the hood which can spray windshield wiper fluid onto the windshield. Windshield wiper fluid serves two major functions. The first function is to clean the windshield of dust, dirt, bugs or other foreign matter which can obscure the driver's vision. Additionally, the windshield wiper fluid is an antifreeze solution which is utilized to remove ice and snow from the windshield.
In the most recent quarter century, there has been a major effort to increase fuel economy of automotive vehicles. A major technical trend to increase fuel economy is to diminish the aerodynamic drag of the vehicle by lowering the hood region of the vehicle. A more rounded or pointed front end has replaced the box front end which was common on many earlier vehicles. Additionally, the grill area is typically smaller. The aerodynamic changes which have occurred on the front of the vehicle have resulted in a smaller volumetric space between the various components under the vehicle hood. Therefore, fluid reservoirs have to be placed in less optimal positions making filling the reservoirs much more difficult.
It is desirable that the windshield wiper fluid reservoir be as large as possible to reduce the frequency of refilling the reservoir. This is especially critical in long distance travel. It is also desirable that the windshield wiper fluid reservoir be placed in a region of the engine compartment which is readily accessible to fill by the vehicle operator regardless of the vehicle operator's height or reach. It is also desirable that the windshield wiper fluid reservoir be placed within a portion of a vehicle underneath the hood wherein there is already space available without requiring redesign or relocation of other engine compartment components of the vehicle.
Another fluid reservoir in the vehicle is the engine coolant overflow reservoir. To increase the efficiency of the vehicle most automotive engines have a pressurized engine coolant system. In a pressurized engine coolant system the amount of coolant in the engine and the radiator combined is not a constant. Accordingly, there is provided an overflow engine coolant reservoir. At certain points of operation of the vehicle, engine coolant will be sucked into the radiator from the engine coolant reservoir. At other times engine coolant will be pushed out of the radiator back into the engine coolant reservoir. When the engine coolant system is fully pressurized and the engine is hot, it can be hazardous to remove the radiator cap. Additionally, it is not always prudent to add low temperature engine coolant to the engine coolant system when the engine is hot. To prevent a vehicle operator from having to remove a radiator cap and to prevent the addition of cold coolant to a hot engine, engine coolant is typically added to the engine coolant overflow reservoir.
It is desirable that the engine coolant overflow reservoir be as large as possible so that a frequency of refilling the reservoir can be reduced. This is especially critical in vehicles which do not receive proper maintenance, since low coolant levels can lead to catastrophic failure of the engine. It is also desirable that the engine coolant overflow reservoir be placed in a region of the engine compartment which is readily accessible to fill by the vehicle operator regardless of the vehicle operator's height or reach. It is also desirable that the engine coolant overflow reservoir be convenient to fill, thereby eliminating spills of expensive engine antifreeze and the resultant unpleasant odor from engine coolant on a hot engine block. It is also desirable that the engine coolant overflow reservoir be placed within a portion of a vehicle underneath the hood wherein there is already space available without requiring redesign or relocation of other engine compartment components of the vehicle.